Hi
We can pass variadic arguments as a array to any variadic function. But
some our old variadic functions doesn't supports this feature.
We cannot to write
SELECT least(VARIADIC ARRAY[1,2,3]);
Attached patch add this possibility to least, greatest functions.
Regards
Pavel
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 885da18306..53021b1ae2 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1852,13 +1852,18 @@ ExecInitExprRec(Expr *node, ExprState *state,
case T_MinMaxExpr:
{
MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
- int nelems = list_length(minmaxexpr->args);
+ int nelems;
TypeCacheEntry *typentry;
FmgrInfo *finfo;
FunctionCallInfo fcinfo;
ListCell *lc;
int off;
+ if (minmaxexpr->args)
+ nelems = list_length(minmaxexpr->args);
+ else
+ nelems = 1;
+
/* Look up the btree comparison function for the datatype */
typentry = lookup_type_cache(minmaxexpr->minmaxtype,
TYPECACHE_CMP_PROC);
@@ -1895,16 +1900,29 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.minmax.finfo = finfo;
scratch.d.minmax.fcinfo_data = fcinfo;
- /* evaluate expressions into minmax->values/nulls */
- off = 0;
- foreach(lc, minmaxexpr->args)
+ if (minmaxexpr->args)
{
- Expr *e = (Expr *) lfirst(lc);
+ scratch.d.minmax.variadic_arg = false;
- ExecInitExprRec(e, state,
- &scratch.d.minmax.values[off],
- &scratch.d.minmax.nulls[off]);
- off++;
+ /* evaluate expressions into minmax->values/nulls */
+ off = 0;
+ foreach(lc, minmaxexpr->args)
+ {
+ Expr *e = (Expr *) lfirst(lc);
+
+ ExecInitExprRec(e, state,
+ &scratch.d.minmax.values[off],
+ &scratch.d.minmax.nulls[off]);
+ off++;
+ }
+ }
+ else
+ {
+ scratch.d.minmax.variadic_arg = true;
+
+ ExecInitExprRec(minmaxexpr->variadic_arg, state,
+ &scratch.d.minmax.values[0],
+ &scratch.d.minmax.nulls[0]);
}
/* and push the final comparison */
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index c08df6f162..e26487d315 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -2791,6 +2791,53 @@ ExecEvalMinMax(ExprState *state, ExprEvalStep *op)
/* default to null result */
*op->resnull = true;
+ if (op->d.minmax.variadic_arg)
+ {
+ ArrayIterator array_iterator;
+ ArrayType *arr;
+ Datum value;
+ bool isnull;
+
+ if (nulls[0])
+ return;
+
+ arr = DatumGetArrayTypeP(values[0]);
+
+ array_iterator = array_create_iterator(arr, 0, NULL);
+ while (array_iterate(array_iterator, &value, &isnull))
+ {
+ if (isnull)
+ continue;
+
+ if (*op->resnull)
+ {
+ /* first nonnull input */
+ *op->resvalue = value;
+ *op->resnull = false;
+ }
+ else
+ {
+ int cmpresult;
+
+ /* apply comparison function */
+ fcinfo->arg[0] = *op->resvalue;
+ fcinfo->arg[1] = value;
+
+ fcinfo->isnull = false;
+ cmpresult = DatumGetInt32(FunctionCallInvoke(fcinfo));
+ if (fcinfo->isnull) /* probably should not happen */
+ continue;
+
+ if (cmpresult > 0 && operator == IS_LEAST)
+ *op->resvalue = value;
+ else if (cmpresult < 0 && operator == IS_GREATEST)
+ *op->resvalue = value;
+ }
+ }
+
+ return;
+ }
+
for (off = 0; off < op->d.minmax.nelems; off++)
{
/* ignore NULL inputs */
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index e8ea59e34a..3df2d42ad6 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -1942,6 +1942,7 @@ _copyMinMaxExpr(const MinMaxExpr *from)
COPY_SCALAR_FIELD(inputcollid);
COPY_SCALAR_FIELD(op);
COPY_NODE_FIELD(args);
+ COPY_NODE_FIELD(variadic_arg);
COPY_LOCATION_FIELD(location);
return newnode;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 3bb91c9595..1c6fddac2a 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -634,6 +634,7 @@ _equalMinMaxExpr(const MinMaxExpr *a, const MinMaxExpr *b)
COMPARE_SCALAR_FIELD(inputcollid);
COMPARE_SCALAR_FIELD(op);
COMPARE_NODE_FIELD(args);
+ COMPARE_NODE_FIELD(variadic_arg);
COMPARE_LOCATION_FIELD(location);
return true;
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index a10014f755..2fbdcd78f8 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -465,6 +465,9 @@ exprTypmod(const Node *expr)
int32 typmod;
ListCell *arg;
+ if (mexpr->variadic_arg)
+ return exprTypmod((Node *) mexpr->variadic_arg);
+
if (exprType((Node *) linitial(mexpr->args)) != minmaxtype)
return -1;
typmod = exprTypmod((Node *) linitial(mexpr->args));
@@ -2065,7 +2068,15 @@ expression_tree_walker(Node *node,
case T_CoalesceExpr:
return walker(((CoalesceExpr *) node)->args, context);
case T_MinMaxExpr:
- return walker(((MinMaxExpr *) node)->args, context);
+ {
+ MinMaxExpr *mexpr = (MinMaxExpr *) node;
+
+ if (walker(mexpr->args, context))
+ return;
+ if (walker(mexpr->variadic_arg, context))
+ return true;
+ }
+ break;
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
@@ -2811,6 +2822,7 @@ expression_tree_mutator(Node *node,
FLATCOPY(newnode, minmaxexpr, MinMaxExpr);
MUTATE(newnode->args, minmaxexpr->args, List *);
+ MUTATE(newnode->variadic_arg, minmaxexpr->variadic_arg, Expr *);
return (Node *) newnode;
}
break;
@@ -3329,7 +3341,15 @@ raw_expression_tree_walker(Node *node,
case T_CoalesceExpr:
return walker(((CoalesceExpr *) node)->args, context);
case T_MinMaxExpr:
- return walker(((MinMaxExpr *) node)->args, context);
+ {
+ MinMaxExpr *mexpr = (MinMaxExpr *) node;
+
+ if (walker(mexpr->args, context))
+ return true;
+ if (walker(mexpr->variadic_arg, context))
+ return true;
+ }
+ break;
case T_XmlExpr:
{
XmlExpr *xexpr = (XmlExpr *) node;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 69731ccdea..0eddbd1a3b 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1597,6 +1597,7 @@ _outMinMaxExpr(StringInfo str, const MinMaxExpr *node)
WRITE_OID_FIELD(inputcollid);
WRITE_ENUM_FIELD(op, MinMaxOp);
WRITE_NODE_FIELD(args);
+ WRITE_NODE_FIELD(variadic_arg);
WRITE_LOCATION_FIELD(location);
}
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index e117867de5..ca9ef21136 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1086,6 +1086,7 @@ _readMinMaxExpr(void)
READ_OID_FIELD(inputcollid);
READ_ENUM_FIELD(op, MinMaxOp);
READ_NODE_FIELD(args);
+ READ_NODE_FIELD(variadic_arg);
READ_LOCATION_FIELD(location);
READ_DONE();
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6d23bfb0b3..99bacaa2fc 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -13848,6 +13848,22 @@ func_expr_common_subexpr:
v->location = @1;
$$ = (Node *)v;
}
+ | GREATEST '(' VARIADIC a_expr ')'
+ {
+ MinMaxExpr *v = makeNode(MinMaxExpr);
+ v->variadic_arg = $4;
+ v->op = IS_GREATEST;
+ v->location = @1;
+ $$ = (Node *)v;
+ }
+ | LEAST '(' VARIADIC a_expr ')'
+ {
+ MinMaxExpr *v = makeNode(MinMaxExpr);
+ v->variadic_arg = $4;
+ v->op = IS_LEAST;
+ v->location = @1;
+ $$ = (Node *)v;
+ }
| XMLCONCAT '(' expr_list ')'
{
$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 385e54a9b6..2520d62610 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2258,35 +2258,60 @@ transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m)
MinMaxExpr *newm = makeNode(MinMaxExpr);
List *newargs = NIL;
List *newcoercedargs = NIL;
- const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
- ListCell *args;
newm->op = m->op;
- foreach(args, m->args)
+
+ if (m->args)
{
- Node *e = (Node *) lfirst(args);
- Node *newe;
+ ListCell *args;
+ const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
- newe = transformExprRecurse(pstate, e);
- newargs = lappend(newargs, newe);
- }
+ foreach(args, m->args)
+ {
+ Node *e = (Node *) lfirst(args);
+ Node *newe;
- newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
- /* minmaxcollid and inputcollid will be set by parse_collate.c */
+ newe = transformExprRecurse(pstate, e);
+ newargs = lappend(newargs, newe);
+ }
- /* Convert arguments if necessary */
- foreach(args, newargs)
+ newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
+ /* minmaxcollid and inputcollid will be set by parse_collate.c */
+
+ /* Convert arguments if necessary */
+ foreach(args, newargs)
+ {
+ Node *e = (Node *) lfirst(args);
+ Node *newe;
+
+ newe = coerce_to_common_type(pstate, e,
+ newm->minmaxtype,
+ funcname);
+ newcoercedargs = lappend(newcoercedargs, newe);
+ }
+
+ newm->args = newcoercedargs;
+ }
+ else
{
- Node *e = (Node *) lfirst(args);
- Node *newe;
+ Oid input_type;
+ Oid element_typeid;
- newe = coerce_to_common_type(pstate, e,
- newm->minmaxtype,
- funcname);
- newcoercedargs = lappend(newcoercedargs, newe);
+ Assert(m->variadic_arg);
+
+ newm->variadic_arg = transformExprRecurse(pstate, (Node *) m->variadic_arg);
+ input_type = exprType(newm->variadic_arg);
+
+ if (input_type == InvalidOid)
+ elog(ERROR, "cannot to determinate result type");
+
+ element_typeid = get_base_element_type(input_type);
+ if (!OidIsValid(element_typeid))
+ elog(ERROR, "expected a array parameter");
+
+ newm->minmaxtype = element_typeid;
}
- newm->args = newcoercedargs;
newm->location = m->location;
return (Node *) newm;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 29884f1c8b..8e56829345 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8443,7 +8443,17 @@ get_rule_expr(Node *node, deparse_context *context,
appendStringInfoString(buf, "LEAST(");
break;
}
- get_rule_expr((Node *) minmaxexpr->args, context, true);
+
+ if (minmaxexpr->args)
+ {
+ get_rule_expr((Node *) minmaxexpr->args, context, true);
+ }
+ else
+ {
+ appendStringInfoString(buf, "VARIADIC ");
+ get_rule_expr((Node *) minmaxexpr->variadic_arg, context, true);
+ }
+
appendStringInfoChar(buf, ')');
}
break;
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 02af68f2c2..7debc2e598 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -453,6 +453,7 @@ typedef struct ExprEvalStep
/* workspace for argument values */
Datum *values;
bool *nulls;
+ bool variadic_arg;
int nelems;
/* is it GREATEST or LEAST? */
MinMaxOp op;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index b886ed3534..acbb7226c1 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1087,6 +1087,7 @@ typedef struct MinMaxExpr
Oid inputcollid; /* OID of collation that function should use */
MinMaxOp op; /* function to execute */
List *args; /* the arguments */
+ Expr *variadic_arg; /* the variadic argument */
int location; /* token location, or -1 if unknown */
} MinMaxExpr;
